assume cs:code

a segment

    db 1, 2, 3, 4, 5, 6, 7, 8

a ends

b segment

    db 1, 2, 3, 4, 5, 6, 7, 8
    
b ends

c segment

    db 0, 0, 0, 0, 0, 0, 0, 0

c ends

code segment

start:

    mov cx, 8
    mov bx, 0

procedure:

    mov dx, 0

    mov ax, a
    mov ds, ax
    add dx, [bx]

    mov ax, b
    mov ds, ax
    add dx, [bx]

    mov ax, c
    mov ds, ax
    mov [bx], dx

    inc bx

    loop procedure

    mov ax, 4c00h
    int 21h

code ends

end start